Outdoor enclosures for electronic systems and telecommunications systems are known. Some enclosures also include batteries, such as valve-regulated lead acid (VRLA) batteries as a backup power supply for the electronics. It is important to regulate the temperature of the inside of the enclosure to specified levels. This is necessary in order to ensure the proper operation of the electronics and also the batteries.
If the equipment within the enclosure produces a large amount of heat, the only method of cooling that is adequate for the task is direct air cooling. For other equipment which is less demanding, an air conditioner may be sufficient. Active electronic or telecommunications equipment will operate properly at temperatures up to 50, 55 or even 65° C. However, if batteries are present within the same enclosure, the batteries rapidly lose the ability to retain a charge if the temperatures exceed 30° C. for an extended period of time. Thus, some form of air-conditioning is necessary to maintain the temperatures of the batteries near 25° C.
While the use of air conditioning to keep the batteries at a proper temperature is often necessary, there is an expense associated with running such an air conditioner. Reducing the cost of cooling the enclosure is a desirable feature in order to reduce the overall costs of running the equipment.